macosx: Fix playing an item always doing so in library playback mode rather than single item mode

Caused by bad fix for unknown parent group types (which should always
play in single item mode)

Signed-off-by: Claudio Cambra <developer@claudiocambra.com>

modules/gui/macosx/library/VLCLibraryRepresentedItem.m

@@ -270,7 +270,7 @@
 - (void)playImmediately:(BOOL)playImmediately
 {
     VLCPlaylistController * const playlistController = VLCMain.sharedInstance.playlistController;
-    if (playlistController.libraryPlaylistMode || self.parentType != VLCMediaLibraryParentGroupTypeUnknown) {
+    if (playlistController.libraryPlaylistMode && self.parentType != VLCMediaLibraryParentGroupTypeUnknown) {
         [self playLibraryModeImmediately:playImmediately];
     } else {
         [self playIndividualModeImmediately:playImmediately];